(a) A public utility having sewers, conduits, utilidors, poles, pole lines, pipes, pipelines, mains, or other distribution or transmission facilities shall, for a reasonable compensation, permit another public utility to use them when the public convenience and necessity require this use and the use will not result in substantial injury to the owner, or in substantial detriment to the service to the customers of the owners. The cost of modifications or additions necessary to a joint use shall be at the expense of the public utility requesting the use of the facilities.
(b) A telecommunications utility shall permit connection to be made and service to be furnished between a system operated by it and the system or toll facilities operated by another public utility or with the communications facility or system of a nonutility, or between its toll facilities and the toll facilities of another public utility, when public convenience and necessity require the connection and the connection will not result in substantial injury to the owner or other users of the facilities of either public utility or in substantial detriment to the service of either public utility.
(c) The tariff of a public utility shall include rules setting out the terms and conditions under which it will construct, or permit its customers or subscribers to construct, and install lines, cables, radio links, or pipes from its existing facilities to the premises of applicants for service.